Foundation piles are generally constructed from cylindrical foundation pile segments arranged one on top of the other and connected to one another. The foundation pile segments, in turn, are made up of one, two or more partial-cylinder segments, each produced from a bent steel plate.
When a foundation pile segment is produced from just one single partial-cylinder segment, the steel plate is bent along the longitudinal extent thereof in such a way that the longitudinal edges (edges of the material or plate), which lie opposite one another in the bent state, can be welded to one another. Welding of the mutually opposite longitudinal edges is accomplished by means of a longitudinal weld seam.
When a foundation pile segment is produced from two or more partial-cylinder segments, the partial-cylinder segments are each connected to one another at the longitudinal edges by means of longitudinal weld seams. In this case, a number of longitudinal weld seams corresponding to the number of partial-cylinder segments is required to connect the partial-cylinder segments.
The foundation pile is then assembled from a multiplicity of correspondingly formed foundation pile segments by connecting mutually adjoining foundation pile segments by means of respective circular weld seams in such a way that the respective longitudinal axes of the foundation pile segments extend in a collinear manner relative to one another.
To produce a corresponding foundation pile, therefore, a large number of weld seams with a large total length is required, making the production of the foundation pile complex and expensive. Thus, for example, to produce two foundation pile segments, each having a height of 3 m and a diameter of 7 m, and for the connection thereof, weld seams with a total length of 28 m are required, namely two times 3 m of longitudinal weld seam in each case to connect the mutually opposite lateral edges or edges of the material of the individual partial-cylinder segments and 22 m of circular weld seam to connect the two foundation pile segments.
In the case of foundation piles which are anchored in the seabed, diameters of 7 m (seven meters) and more are currently customary or desired. To ensure that a foundation pile has sufficient stability to withstand forces exerted on said pile by wind and water movements, the wall thickness of the foundation pile must be increased. In addition, there is the problem that, the larger the diameter of a foundation pile, the less effect enlarging the wall thickness has on the stability thereof. In the case of foundation piles with ever-larger diameters, therefore, the wall thicknesses must increase in a disproportionate way relative to the diameter thereof.
However, large wall thicknesses lead to considerable extra work and considerable additional costs in the production of a foundation pile. Bending a steel plate to form a partial-cylinder segment becomes ever more laborious with increasing wall thickness. Moreover, welding partial-cylinder segments together to form a foundation pile segment and welding the foundation pile segments together to form a foundation pile is technically ever more complex and hence also more expensive as the wall thickness increases.